Downsizing of image forming apparatuses has been demanded recently. In response to such a demand, downsizing is achieved in an image forming apparatus including a touch panel in a manner that hardware keys are removed while a soft key array is displayed on the touch panel (screen). However, the soft key array displayed on the touch panel may occupy a display region of the touch panel.
In a keyboard display device disclosed in Patent Literature 1, video signals and a software keyboard displayed on a screen are synthesized and displayed as a screen. In a situation in which a user performs input using the keyboard, the keyboard is displayed opaquely or at low transparency. When no input is performed on the keyboard even after elapse of a predetermined time period, the keyboard is displayed at high transparency. The user checks a content displayed on the screen through the keyboard displayed at the high transparency.